Different trig algorithms in CAS and Home?

[TheKaneB]

Hi,

I couldn't find this while searching through the forum, if it has been already discussed I'm sorry for the double post.

Anyway, if I do the following function in CAS and in Home I get 2 different answers (radians mode):

Home:
TAN(355/226) = −7497089.06508

CAS:
approx(TAN(355/226)) = −7497258.47868

The CAS result is more accurate than the Home result. Anybody knows the reason why they differ? Also, is the CAS trig implementation really different or is it a quirk of the approx() function?

For reference, WolframAlpha says that the answer is -7.4972581853255871129050718318912486634172679437852631..... 10^6

The CAS version got 7 digits correct, while the Home version only calculated 4 correct digits. (I am assuming that all the digits from WolframAlpha are correct, which I think is what all of us will expect).